San Francisco, officially the City and County of San Francisco, is a commercial, financial, and cultural center of Northern California. With an estimated population of 827,526 residents as of 2024, San Francisco proper is the fourth-most populous city in the U.S. state of California and the 17th-most populous in the United States. Among U.S. cities proper with over 300,000 residents, San Francisco is ranked second by population density, first by per capita income, and sixth by aggregate income as of 2023. Depending on how its borders are defined, the broader San Francisco metropolitan area or San Francisco Bay Area is home to 4.6–9.2 million residents. In 2024, the U.S. Census Bureau reported an estimated population of 4,648,486 for the city's metropolitan statistical area (13th-largest in the U.S.) and 9,164,058 residents for the larger combined statistical area (5th-largest).
Prior to European settlement, the modern city proper was inhabited by the Yelamu Ohlone. On June 29, 1776, settlers from New Spain established the Presidio of San Francisco at the Golden Gate, and the Mission San Francisco de Asís a few miles away, both named for Francis of Assisi. The California gold rush of 1849 brought rapid growth, making it the largest city on the West Coast at the time. In 1856, San Francisco became a consolidated city-county. After three-quarters of the city was destroyed by the 1906 earthquake and fire, it was quickly rebuilt, hosting the Panama–Pacific International Exposition nine years later. In World War II, it was a major port of embarkation for naval service members shipping out to the Pacific Theater. After the war, the confluence of returning servicemen, significant immigration, liberalizing attitudes, the rise of the beatnik and hippie countercultures, the sexual revolution, opposition to U.S. involvement in the Vietnam War, and other factors led to the Summer of Love and the gay rights movement, cementing San Francisco as a center of liberal activism.
